A 31-year-old man comes to the emergency department because of a high-grade fever and multiple painful skin nodules that began 2 days ago. The skin lesions are red and painful, and gradually developed on both arms before spreading to the chest and legs. He also notes fatigue, poor appetite, dry cough, and mild shortness of breath. One week ago, the patient was helping his father in the garden.
The patient had an allogeneic bone marrow transplantation for acute leukemia 3 months ago complicated by pneumonia, catheter-associated bacteremia, and chronic gastrointestinal graft-versus-host-disease. His medications include prednisone, valganciclovir, and trimethoprim/sulfamethoxazole.
His temperature is 39.4 C (103.0 F), blood pressure is 90/60 mm Hg, pulse is 106/min, and respirations are 28/min. Examination shows dry mucus membranes, diffuse crackles in the lung fields, and mild splenomegaly. Skin examination reveals dry skin with multiple raised, erythematous, and tender nodules on his upper extremities, lower extremities, and upper chest.
Laboratory results are as follows:

The patient is admitted to the hospital and started on empiric antibiotic therapy. Blood cultures are obtained and grow mold-like organisms.
Which of the following is the most likely cause of his condition?

Question

A 31-year-old man comes to the emergency department because of a high-grade fever and multiple painful skin nodules that began 2 days ago.  The skin lesions are red and painful, and gradually developed on both arms before spreading to the chest and legs.  He also notes fatigue, poor appetite, dry cough, and mild shortness of breath.  One week ago, the patient was helping his father in the garden.
The patient had an allogeneic bone marrow transplantation for acute leukemia 3 months ago complicated by pneumonia, catheter-associated bacteremia, and chronic gastrointestinal graft-versus-host-disease.  His medications include prednisone, valganciclovir, and trimethoprim/sulfamethoxazole.  
His temperature is 39.4 C (103.0 F), blood pressure is 90/60 mm Hg, pulse is 106/min, and respirations are 28/min.  Examination shows dry mucus membranes, diffuse crackles in the lung fields, and mild splenomegaly.  Skin examination reveals dry skin with multiple raised, erythematous, and tender nodules on his upper extremities, lower extremities, and upper chest.
Laboratory results are as follows:

The patient is admitted to the hospital and started on empiric antibiotic therapy.  Blood cultures are obtained and grow mold-like organisms.
Which of the following is the most likely cause of his condition?

Quizplus · Accepted Answer

11ec193a_9620_75f7_853d_773cd685d2f6_MD0002_00 This patient's presentation is most concerning for Fusarium species, which is the second most common pathogenic mold. Fusarium is found in soil and plant debris and directly invades tissue to cause destruction. Invasive disease most commonly occurs in severely immunosuppressed patients (i.e., neutropenia, lymphopenia, graft-vs-host disease, and corticosteroids), particularly those with hematologic malignancies receiving induction chemotherapy or bone marrow transplantation. Patients typically present with refractory fever (> 90%) to antibacterial and/or antifungal therapy, skin lesions (precede fungemia by approximately 5 days), and sinopulmonary infections (~75%). Fusarium Diagnosis is suggested by skin biopsy (> 50% of patients) and/or positive blood cultures (~40% of patients) that usually grow a mold. Patients without a definitive skin biopsy diagnosis require tissue biopsy. Fusarium is resistant to many antifungal agents and carries a high mortality (60-80%) in immunocompromised patients, particularly those who are neutropenic or taking steroids. High-dose amphotericin B and/or voriconazole are most often used with varying degrees of success. Prevention is key with patients avoiding tap water or soil contact to areas of broken skin. (Choice A) Aspergillus fumigatus may cause pneumonia and skin lesions, but usually does not have positive blood cultures. Immunocompromised patients also tend to present more often with pulmonary complaints progressing to multi-organ failure rather than primary skin lesions. Aspergillus fumigatus (Choice B) Candida albicans is a diploid fungus rather than a mold. Also, C. albicans typically presents in the first 60 days after organ transplantation with clusters of painless pustules on an erythematous base. (Choice D) Histoplasma capsulatum is a fungus that is rare in bone marrow transplant patients, but more common in patients with HIV, solid organ transplants, and in those taking anti-TNF therapy. (Choice E) Nocardia is a weakly staining gram-positive, rod-shaped bacteria that forms partially acid-fast beaded branching filaments. Nocardiosis with skin disease usually presents as ulcerations, pyoderma, cellulitis, nodules, and subcutaneous abscesses. Nocardia Educational objective: Fusariosis can occur in severely immunocompromised patients. Inoculation commonly occurs when breaks in the skin are exposed to tap water or soil. Patients can present with refractory fever, skin lesions, and pulmonary disease. Diagnosis is suggested by skin biopsy (> 50% of patients) and/or positive blood cultures (~40% of patients) that usually grow a mold. Treatment is with amphotericin B +/- voriconazole with varying efficacy. __________ References: Disseminated fusariosis in immunocompromised patients. (http://www.ncbi.nlm.nih.gov/pubmed/21708518) The challenge of managing fusariosis. (http://www.ncbi.nlm.nih.gov/pubmed/21304267)

A 31-Year-Old Man Comes to the Emergency Department Because of a High-Grade